feat(pm-agent): an in-cluster AI Program Manager that turns Gitea issues into pull requests

A service that reads this repository's Gitea issues, decides what to do about each
thread as the Program Manager persona, and runs one worker agent per assignment that
authors a change, runs the merge gate and opens a pull request. It reacts to issue
creation and to comments; the assignment and all correspondence travel through the
issue thread and the PR. It authenticates with an Anthropic subscription token. It
never pushes to main and never merges.

Three choices carry the design, with alternatives recorded in docs/plans/:
 - it POLLS rather than receiving webhooks (Gitea's webhook SSRF guard, lost
   deliveries, and no inbound reach needed at all);
 - it keeps NO state: the trigger is "the newest thing in this thread was not
   written by me", so the issue thread is the state — no PVC, no backup obligation;
 - the model holds NO tools: its reply is one JSON object this code validates, so
   nothing in the path executes text.

The boundary is platform/kyverno/admission/pm-agent-job-shape.yaml (Enforce,
failurePolicy: Fail), not the RBAC: Kubernetes places no `use` check on
serviceAccountName, so "may create Jobs" is "may run arbitrary code as the
namespace's most privileged identity". Six rules admit only the committed shape, and
the worker identity is bound to nothing with no token mounted, so there is nothing to
escalate to. 28/28 offline Kyverno assertions.

Nothing has run: the image has never been built or pushed, and both the image digest
and the two credentials are deliberate placeholders. See the handoff entry's
"What I did NOT verify".

Refs CLAUDE.md §1/§3/§6, R-SEC-02, R-GITOPS-02.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

catalog/gitea.yaml

@@ -208,6 +208,19 @@ inClusterClients:
     namespace: flux-system      # matched by NAMESPACE alone — the flux controllers' pod labels belong
                                 # to upstream's manifests, not to this platform's contract
     port: 3000                  # ONLY the Gitea HTTP port — the same single port the Gateway allow opens
+  # The PM agent service (platform/pm-agent/). Its dispatcher reads issues and posts comments
+  # over this port, and every worker Job clones, pushes and opens pull requests over it. Like
+  # Flux's source-controller above, it dials the ClusterIP DIRECTLY — deliberately, so the
+  # agent's path to the repository depends on neither public DNS, nor Cloudflare, nor the
+  # shared Gateway, nor ${BASE_DOMAIN}. And exactly as for Flux, that means this namespace's
+  # own default-deny (R-NET-01) DROPS the connection unless it is declared here: without this
+  # entry the dispatcher's egress allow is satisfied and the packet is still discarded at the
+  # Gitea end, which presents as an authentication timeout rather than as a policy denial.
+  # That is the 2026-09-13 lesson documented at length above, applied before it is relearned.
+  - name: pm-agent
+    namespace: pm-agent         # matched by NAMESPACE alone, so the dispatcher Deployment and every
+                                # ephemeral worker Job are covered by the one declaration
+    port: 3000                  # ONLY the Gitea HTTP port
 auth:
   mode: oidc                    # native Keycloak OIDC client (docs/13 SSO row, docs/15 "Native OIDC" set; R-IDP-02)
   groups: